I've had my Creality Ender 3 Pro since October 2019. It was running like a dream until about a month ago. The Z-axis started knocking prints off the plate during printing. I've changed mats and worked on adhesion issues. I've switched to a glass plate and triple checked that it is level. I checked to see if it was binding but honestly I couldn't tell.

I'm at a loss of what to do to troubleshoot and fix the issue. Any suggestions?

It homes fine and manual controls work fine with no issues.

  • $\begingroup$ Welcome to 3dPrinting.SE! $\endgroup$ Dec 23, 2019 at 19:44
  • 1
    $\begingroup$ Can you explain what you mean by the "Z axis knocking prints off"? What part actually collides or moves in a manner that's unexpected/erroneous? $\endgroup$ Dec 23, 2019 at 20:03
  • $\begingroup$ can you check if your Potal (X-Axis) is orthogonal to the vertical bars? knocking it off is a known issiue. $\endgroup$
    – Trish
    Dec 25, 2019 at 19:02
  • $\begingroup$ Did you ever find out what happened? Please add an answer if you did! $\endgroup$
    – Jason
    Aug 17, 2020 at 12:33
  • $\begingroup$ did you get an answer to this? I'm having the same issue and the z axis keeps dropping during prints at regular intervals above a certain height, as if it can't hold itself up (all screws seem to be right, and there's no binding it just isn't holding itself at the right height)? $\endgroup$
    – Willow
    Jan 9, 2021 at 10:18

1 Answer 1


Can you send a link to a short video of the problem occuring? It might be because of multiple factors but we will be able to identify if there's a video of it.

Possible reasons:

  • Z axis nut might be too tight. This would cause the nut to bind with the leadscrew and so the motor will not be able to lift the z-axis further while printing.

  • Not enough retraction. This would cause filament to ooze from the nozzle during travel moves and this filament would collide with the printed object, causing it to be knocked off. A possible solution for this would be to enable Z-hop in the slider, have the hop distance set to at least 1.5x the layer height you are currently printing with.

  • Too small of a contact area. This usually happens more often for tall prints. A solution would be to increase brim in the slicer settings (at least 10~15 lines) to increase the adhesion of the print and the bed.

  • Dirty nozzle. Old prints filament may be stuck on the outer face of the nozzle and might be catching onto the printed part while printing.


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